For the west coast of Scotland, the Highlands and Islands and Northern Ireland, the Met Office has upgraded its warning to amber ''be prepared'' status.

The public were warned to expect dangerous conditions, especially along causeways and coastal roads exposed to the west.

High winds are also set to hit northern parts of England and Wales, with yellow "be aware'' warnings in place.

Steve Willington, chief meteorologist at the Met Office, said: "Very strong winds are likely to affect northern and central parts of the UK from early Wednesday and last through until early Thursday as a very deep low pressure system moves slowly eastwards between Scotland and Iceland.

"A period of severe gales is likely over northern and central Britain, as well as the potential for storm force winds over north western coastal areas of Scotland.''

Police warned that travel conditions in the worst-hit areas of Scotland could be "hazardous'', with disruption also expected on ferries, rail services, roads and bridges.

Many ferry services operated by Caledonian MacBrayne, which operates ferries in the west of Scotland, have already been disrupted or hit by cancellations.

Further disruption is likely throughout today as winds are expected to whip up unusually high waves, with sea swells of up to 12 metres in parts.

The Scottish Environment Protection Agency (Sepa) has more than 20 flood alerts and warnings in place, particularly for coastal areas.

Several train services will also be cancelled as a safety precaution, Network Rail and train operator ScotRail announced.

Users of the Forth Road Bridge have been warned to expect significant disruption as the bridge could be closed to all vehicles except cars throughout the day.

The Forth, Kessock and Skye bridges were closed to high-sided vehicles yesterday because of the rising wind speeds.

Western Isles Council said all schools and nurseries there will be closed as the police have advised the public not to travel unless it absolutely necessary.

All depots, libraries, museums and sports facilities in the Western Isles will also be shut.

Looking ahead, Scotland's Deputy First Minister John Swinney has urged people across the country to be on the lookout for travel and safety advice.

''I am confident we are well-placed to cope,'' he said.

Councils south of the border insisted they are prepared for the plunge in temperatures, with gritters ''out in force'' and depots filled with about 1.3 million tonnes of salt.

The Met Office warnings for wind run through today and into tomorrow morning, extending by that stage to cover the whole of the UK.